tests/migration: Fail on unexpected migration states

We've got various places where we wait for a migration to enter
a given state; but if we enter an unexpected state we tend to fail
in odd ways; add a mechanism for explicitly testing for any state
which we shouldn't be in.
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190923131022.15498-2-dgilbert@redhat.com>
Reviewed-by: NCleber Rosa <crosa@redhat.com>
Tested-by: NCleber Rosa <crosa@redhat.com>
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NDr. David Alan Gilbert <dgilbert@redhat.com>

tests/migration-test.c

@@ -255,15 +255,19 @@ static void read_blocktime(QTestState *who)
 }
 
 static void wait_for_migration_status(QTestState *who,
-                                      const char *goal)
+                                      const char *goal,
+                                      const char **ungoals)
 {
     while (true) {
         bool completed;
         char *status;
+        const char **ungoal;
 
         status = migrate_query_status(who);
         completed = strcmp(status, goal) == 0;
-        g_assert_cmpstr(status, !=,  "failed");
+        for (ungoal = ungoals; *ungoal; ungoal++) {
+            g_assert_cmpstr(status, !=,  *ungoal);
+        }
         g_free(status);
         if (completed) {
             return;
@@ -274,7 +278,8 @@ static void wait_for_migration_status(QTestState *who,
 
 static void wait_for_migration_complete(QTestState *who)
 {
-    wait_for_migration_status(who, "completed");
+    wait_for_migration_status(who, "completed",
+                              (const char * []) { "failed", NULL });
 }
 
 static void wait_for_migration_pass(QTestState *who)
@@ -809,7 +814,9 @@ static void test_postcopy_recovery(void)
      * Wait until postcopy is really started; we can only run the
      * migrate-pause command during a postcopy
      */
-    wait_for_migration_status(from, "postcopy-active");
+    wait_for_migration_status(from, "postcopy-active",
+                              (const char * []) { "failed",
+                                                  "completed", NULL });
 
     /*
      * Manually stop the postcopy migration. This emulates a network
@@ -822,7 +829,9 @@ static void test_postcopy_recovery(void)
      * migrate-recover command can only succeed if destination machine
      * is in the paused state
      */
-    wait_for_migration_status(to, "postcopy-paused");
+    wait_for_migration_status(to, "postcopy-paused",
+                              (const char * []) { "failed", "active",
+                                                  "completed", NULL });
 
     /*
      * Create a new socket to emulate a new channel that is different
@@ -836,7 +845,9 @@ static void test_postcopy_recovery(void)
      * Try to rebuild the migration channel using the resume flag and
      * the newly created channel
      */
-    wait_for_migration_status(from, "postcopy-paused");
+    wait_for_migration_status(from, "postcopy-paused",
+                              (const char * []) { "failed", "active",
+                                                  "completed", NULL });
     migrate(from, uri, "{'resume': true}");
     g_free(uri);